COHN Toxicology and Biohazards 4 — Questions and Answers
Question 1: A battery manufacturing worker with elevated blood lead level (BLL) of 50 µg/dL is asymptomatic. According to OSHA's Lead Standard, the occupational health nurse should:
- Allow continued work exposure because the worker has no symptoms
- Remove the worker from lead exposure until BLL falls below 40 µg/dL (Correct answer)
- Recommend chelation therapy immediately without medical removal
- Retest in 6 months and return to work in the interim
Correct answer: Remove the worker from lead exposure until BLL falls below 40 µg/dL
OSHA's Lead Standard (29 CFR 1910.1025) requires medical removal when BLL reaches 50 µg/dL, with return to work prohibited until BLL falls below 40 µg/dL on two successive tests.
Question 2: Which class of fire extinguisher is appropriate for a fire involving energized electrical equipment?
- Class A
- Class B
- Class C (Correct answer)
- Class D
Correct answer: Class C
Class C extinguishers use non-conductive extinguishing agents (CO₂ or dry chemical) safe for energized electrical equipment, where water-based Class A agents would create electrocution risk.
Question 3: A semiconductor fabrication worker is exposed to arsine (AsH₃) gas. The MOST critical early target organ affected by acute arsine toxicity is the:
- Liver, causing acute hepatic necrosis
- Red blood cells, causing massive hemolysis (Correct answer)
- Kidneys, causing direct tubular nephrotoxicity
- Lungs, causing chemical pneumonitis
Correct answer: Red blood cells, causing massive hemolysis
Arsine causes rapid, massive hemolysis of red blood cells, leading to hemoglobinuria, acute renal failure (secondary), and potentially fatal anemia — hemolysis is the primary acute mechanism.
Question 4: Which OSHA standard requires employers to label containers of hazardous chemicals and train workers on chemical hazards using a standardized 16-section format?
- Process Safety Management Standard (29 CFR 1910.119)
- Hazard Communication Standard (29 CFR 1910.1200) (Correct answer)
- Emergency Action Plan Standard (29 CFR 1910.38)
- Personal Protective Equipment Standard (29 CFR 1910.132)
Correct answer: Hazard Communication Standard (29 CFR 1910.1200)
OSHA's Hazard Communication Standard (HazCom/GHS) requires Safety Data Sheets in 16-section GHS format, GHS-compliant labeling, and worker training on chemical hazards.
Question 5: A paint shop worker develops contact dermatitis after starting to use a new solvent. The MOST important initial nursing intervention is:
- Prescribe topical corticosteroids and advise continued work
- Identify the causative agent through patch testing and remove exposure (Correct answer)
- Recommend antihistamines and reassure the worker the rash will resolve
- Transfer the worker to another job without investigating the cause
Correct answer: Identify the causative agent through patch testing and remove exposure
Identifying the specific causative agent through patch testing is essential for accurate diagnosis and targeted exposure elimination; symptomatic treatment alone allows continued sensitization.
Question 6: Benzene is classified as a human carcinogen primarily associated with which cancer?
- Mesothelioma
- Lung adenocarcinoma
- Leukemia (particularly AML) (Correct answer)
- Bladder transitional cell carcinoma
Correct answer: Leukemia (particularly AML)
Benzene is a Group 1 IARC carcinogen strongly linked to acute myelogenous leukemia (AML) and other hematological malignancies through bone marrow toxicity.
Question 7: The health effect associated with chronic inhalation of crystalline silica is:
- Asbestosis
- Silicosis (Correct answer)
- Byssinosis
- Siderosis
Correct answer: Silicosis
Crystalline silica inhalation causes silicosis, characterized by progressive fibrotic nodules in lung parenchyma, and also increases risk of lung cancer and tuberculosis.
COHN Toxicology and Biohazards 4
A battery manufacturing worker with elevated blood lead level (BLL) of 50 µg/dL is asymptomatic.
According to OSHA's Lead Standard, the occupational health nurse should: